Dead-endable self-pressure regulating air nozzle

ABSTRACT

Air ejector having discharge pressure-limiting and noisesuppressing nozzle means is provided with valving means actuated by dead-ending said nozzle means against a surface to thereby reduce the downstream pressure of the air at the outlet of said nozzle means for all static conditions.

Unite States Patent Gihel 1 1 Oct. 2 1973 [54] DEAD-ENDABLESELF-PRESSURE 2,256,729 9/1941 Thompson 239/562 X REGULATING ARR MUZZLE3,l29 892 4/1964 Tillman .1 239/586 X 3,445,069 5/1969 Druge 239/586 X[76] Inventor: Stephen B. Gibel, 5846 Edgerton Rd., North Royalton, Ohio44133 Primary ExaminerM. Henson Wood, Jr. Flled: July 1972 AssistantExaminer'John J. Love 21 AppL 273 329 At!0rney-Albert L. Ely, Jr. ct al.

39 [52] U S Cl 2 l54l, 239/553 3, 223394756729, ABSTRACT [51] Int. Cl..B05b11/14 Air H ector having discharge pressure-limiting and [58]noise-suppressing nozzle means is. provided with valv- 5 ing meansactuated by dead-ending said nozzle means 3 against a surface to therebyreduce the downstream pressure of the air at the outlet of said nozzlemeans for [56] Rqerences Cited all static conditions.

UNITED STATES PATENTS 1,781,554 11/1930 Norton t. 251/339 X 9 Claims, 9Drawing Figures DEAD-ENDABLE SELF-PRESSURE REGULATING AIR NOZZLE Thisinvention relates to an imprvement on the Self- Pressure Regulating AirEjector disclosed in my copending application, Ser. No. 162,784, filedJuly 15, 1971, of which this application is a continuation-inpart, and,more particularly, to such an air ejector nozzle which not only willsuppress the noise of pneumatic cleaning lances or blow-guns tooccupationally safe sound-levels and limit the dynamic force of airblasts to safe operating levels despite higher and fluctuating linepressures but, further, more than meet governmental regulations formaximum downstream pressure at the outlet of the cleaning device whenthe device is deadended", i.e., when the discharge outlet is pressedagainst an obstructing surface. Indeed, under such static conditions thedown-stream pressure at the discharge outlet may be reduced to zero inair ejector nozzles made according to this invention.

As pointed out in my above-entitled co-pending application, the normalline pressure of the air supply required in shops for operation of paintsprayers, pneumatic tools, cylinders, valves, and the like, is in theorder of 90 p.s.i., whereas for removing small parts from forming dies,for moving parts along conveyor chutes, and the like, by means ofair-ejector nozzles, the maximum outlet discharge pressure now permittedby occupational safety and health administrative (OSHA) regulations is30 p.s.i. The multi-jet airejector disclosed in my above co-pendingapplication provides ample air for such operations, despite widefluctuations in the available shop-air over normal line pressure at amuch lower sound level, due to the use of a multi-jet plug as disclosedin my US. Pat. No. 3,537,543 to which air is supplied through theorifice of an adjacent internal disk, the orifice being centrallylocated with respect to the plurality of concentricallylocated nozzleports. This device thereby eliminates the need for expensive pressureregulators in the line to the ejector from the high-pressure shop airline and provides a relatively silent blast of air, free frommalfunctioning of internal check valves or pressure reduction by verynoisy aspirating devices which are also subject to tampering and abuse.

Air-ejectors, as such, are also used as blow-guns or cleaning lancesattached to the end of a flexible line. They can then be moved by anoperator for cleaning residual chips and lubricants or cutting oils fromdies and/or cutting tools, for cleaning parts, and to allow selectiveremoval of formed parts from dies and molds.

Such mobility, unfortunately, also permits the accidental or intentionaldead-ending'of their outlets.

The same governmental (OSHA) regulations which limited the dynamicair'stream from an air ejector noz zle also set the same limit on thepermissible downstream pressure when the air at the discharge outlet isstatic, as when the outlet is dead-ended. To meet this standard, twoexpedients are suggested by the regulations, (a) inserting apressure-limiting valve in each line between the ejector and the supplyof high-pressure shop-air, i.e., installing expensive pieces ofequipment which my self-pressure regulating ejector is intended toeliminate or (b) surrounding the outlet of the discharge nozzle with aprotruding porous cone, sleeve, or screen which prevents the outlet frombeing dead-ended and subjected to static pressure and also is intendedto catch chips or other small objects which may be sent flying inhaphazard directions when such a protruding and surrounding guardprevents the outlet from being precisely aimed. This latter alternativewas no solution to the problem of preventing self-pressure regulatingmulti-jet air ejectors as disclosed in my above application from beingdead-ended and developing the full shop-line pressure at the nozzleoutlets; this is due to the absence, under static conditions, of thebackturbulence within my ejector which, under dynamic flow through it,self-limits the outlet pressures to levels meeting or exceeding safetystandards. For some causes not fully understood, any apertured sleeve orcone surrounding the multi-jet nozzles of my ejector and extendingbeyond them a distance sufficient to allow a flow sufficient to allowthe limiting internal back-turbulence to develop also interferes withthe multiplicity of jets so that they are inoperative, or nearly so, toeject or move the parts or substances the ejector is intended to act on.

It is an object and advantage of this invention to modify a multi-jetair ejector, as disclosed and claimed in my above pending application topermit its use on flexible lines as a blow-gun or cleaning lance withoutinterference with its effectiveness due to guard covers or sleeves.Another object and advantage of this invention is that when such an airejector commences to be deadended, it reduces the flow of emitted airand, when fully dead-ended, the static pressure at the outlet ispreferably reduced to zero, thereby eliminating the recoil which couldbe produced if the outlet were under a static full line pressure whendead-ended.

Other objects and advantages of this invention will be apparent from thefollowing specification, claims, and drawings, in which:

FIG. 1 is an end-view of an ejector made according to this invention.

FIG. 2 is a side view, partly in section along the line 2-2 of FIG. 1,of the ejector shown in FIG. 1.

FIG. 3 is an end view of another embodiment of this invention.

FIG. 4 is a side view of the embodiment shown in FIG. 3, being partly insection along the line 4-4 of FIG. 3.

FIG. 5 is a fragmentary view showing a variation of the embodiment shownin FIG. 4.

FIG. 6 is a fragmentary view showing another variation of the embodimentshown in FIG. 4. I I

FIG. 7 is a fragmentary view showing still another variation of theembodiment shown in FIG. 4.

FIG. 8 is a fragmentary view corresponding to FIG. 7 but showing amodification thereof.

FIG. 9 is a fragmentary view corresponding to FIG. 7 but showing anothermodification thereof.

Referring to the drawings, FIGS. 1 and 2 illustrate a self pressureregulating, relatively silent air ejector which, but for one relativelyminor and one major difference, corresponds to the device shown in FIGS.1 and 2 of my co-pending application Ser. No. 162,784. That is, thedevice 10 comprises a casing or sleeve 11 having a pipe-threaded fitting12 permitting attachment by the nut faces 14 to a conventional couplingconnecting the device 10 to a flexible hose leading to a high-pressureshop air line; such a coupling is usually a hand-held, button-operated,quick-opening shut-off valve. The device 10 may thus be manually aimedat the object or material to be moved by the blast of air dischargedwhen the normally-closed shut-off valve is opened. The end of the casing11 opposite the fitting 12 is counter-bored to receive a disk 15 and aplug 20. The plug 20 is provided with a dished inlet face 22 and threeor more outer concentrically-arranged, equallyspaced holes 25 tapered tofunction as nozzles; the size, form, and number of such nozzlepassageway with respect to the length of the plug are preferablyaccording to the proportions of the similar sound-reducing plug 20 shownin my US. Pat. No. 3,537,543. The disk 15 has a central orifice 16; thedishing of the plug 20 and size of the orifice 16 with respect to thenozzle holes 25 are preferably according to the proportions disclosed inmy co-pending application Ser. No. 162,784.

As described so far, the device shown in FIGS. 1 and 2 of thisapplication is the same as shown in my said application, with onerelatively minor difference. To secure the plug 20 and disk 15 withinthe casing 11, if the protruding end of the thinner counter-bored wallof the casing 11 is spun in to reversely fold it against the dischargeface 21 of the plug 20, the plug and disk 15 will be securely locked bya ring or rim thus formed but which thereby protrudes an appreciabledistance beyond the discharge face 21 of the plug 20. In solving theproblems met by this present invention, it has been discovered that theeffect of the parallel multiple jets of air emitted by the nozzles 25 isenhanced if there is a minimal external ring or sleeve protruding beyondthe discharge face 21. Accordingly, the end of the thin casing wall isnow spun in to provide an internal retaining ring 17 of no greaterlength than the thickness of the counter-bored portion of the casing 11.

The major difference between the device as shown in FIGS. 1 and 2 of thedrawings and that shown in my said co-pending application is that thecenter of the plug 20 is-drilled to receive the stem 31 of a valve 30,and the center of the dished inner surface 22 of the plug 20 iscounter-bored to receive the head 32 of the valve so that it issubstantially flush with the center of the dished surface 22. The end ofthe stem 30 protrudes from the plug face 21 only a distance sufficientto insure that just before the retaining ring 17 can be pressed againsta surface, the valve-head 32, slightly larger than the orifice 16, willbe firmly seated on the orifice.

In normal operation, air passing through the orifice 16 will impinge onthe valve head 32 and'seat it in the dished plug surface 22; this air isthen discharged through the nozzles 25 to issue as a multi-jet dischargefrom the plug face 21 with no significant dimunition of the moving forceof a similar quantity of air emitted from a single discharge outlet, butwith very noticeably less noise. And if the full line pressure on theupstream side of the disk should substantially increase, the ouletpressure of the jets from the nozzles 25 will increase only slightly andremain within acceptable operating limits due, apparently, to theback-turbulence created by the inner plug face 22 which therebyautomatically throttles the flow which would be expected to increasethrough the orifice 16.

The ejector shown in FIGS. 1 and 2 permits close and accurate aiming ofthe device 10, without interference by the stem 31; this protruding stemdoes not interfere withthe action of the multiple jets, as has beenfound with a surrounding collar or wall. If, however, the operatorcommences to dead-end the face 21, the valve head 32 will be raised fromits seat, throttling flow through the orifice 16 and shutting off theflow entirely if the device 10 is fully dead-ended, thereby reducing thestatic outlet pressure to zero under such conditions. If the device 10were not equipped with the valve 30, the dead-ending of it to create astatic condition at the discharge face 21 of the plug would terminatethe throttling back-turbulence between the disk 15 and face 22 andcreate a downstream pressure at the face 21 equal to the full linepressure on the upstream side of the disk 15. This would exceedpermissible regulatory standards and create possibly dangerous recoilconditions if the operator did not release the normally closed,manually-opened shut-off valve.

To eliminate the appearance of the valve stem 31 as shown in FIGS. 1 and2 and the possibility of its being accidentally or intentionally bent orbroken so as to interfere with the operation of the valve 30, FIGS. 3 to7 show a variety of modifications wherein the nozzle plug protrudes fromthe casing 11 but is slideably mounted to permit retraction into it.

Thus, referring to FIGS. 3 and 4, the device corresponds to the device10 as shown in FIGS. 1 and 2,

except that the corresponding disk is force-fitted.

to be retained at the seat provided by the deeper counter-bored portionof the casing 111, the end of which is spun in to provide a retainingring 117. A slightly longer plug is provided with a shouldered outer endnormally held against the ring 117 by the pressure of air dischargedthrough the orifice 116 and acting on the dished plug face 122, leavingan internal chamber 133 between the disk and plug. The plug 120 isprovided with parallel tapered nozzle holes corresponding to the nozzleholes 25 shown in FIG. 1. The plug 120 carries a fixed protruding valvehead 132 aligned with the orifice 116. The nozzles 125 provide asilenced multi-jet discharge from the discharge face 121 and theback-turbulence within the chamber 133 created by air from the orificeimpinging on the valve head 132 regulates the normal dynamic dischargepressure. If the device is dead-ended, however, the valve head 132throttles the downstream static pressure at the face 121 to zero as theplug 125 is retracted in the casing 111.

FIG. 5 shows a variation functioning in the same manner as theretractable plug construction shown in FIG. 4. The disk 215, however,carries a central tubular orifice 216 extending into the chamber 233.The plug 220, provided with nozzles 225, is slidable in the counter boreof the casing 211 and carries a short valve plug 232, which may be ofrelatively softer material, such as nylon, to insure closure of theorifice 216.

FIG. 6 shows a variation substantially identical to that in FIG. 5 witha corresponding casing 311, disk 315, orifice 316, plug 320, nozzles 325and chamber 333. Rather than a valve stem, however, the plug 320 carriesan inserted seat 332 against which the tubular orifice 316 seats whenthe plug is retracted in the eas- FIG. 7 shows a modificationcorresponding in some respects more nearly to that shown in FIG. 4,having a corresponding casing 411, a disk 415 having a central orifice416 and a slidable plug 420 with multi-jet nozzles 425. To secureself-pressure regulation similar to that achieved by the embodimentshown in FIGS. 1 and 2, the plug 420 carries a disk 435 having lateralorifices 436, which are shown for purposes of illustration assubstantially aligned with the nozzles 425, but are preferably offset tocreate greater back turbulence between the disk $35 and the dished faceof the plug 420. The disk 435 carries a stem 437 aligned with theorifice H6 so as to close it when the plug is fully retracted.

The modification shown in FIG. 8 corresponds to that shown in FIG. 7,except for a reversal of the centrally and laterally orificed disks.That is, the casing 511 carries a slidable plug 520 having multi-jetnozzles 525, the plug, in turn, carrying a disk 515 having a centralorifice 5 16 opening onto the dished face of the plug 520. The bottom ofthe counter-bore carries a disk 535 having lateral orifices 536 and acentral valve stem 537 which throttles the orifice 516 when the plug isretracted.

The modification shown in FIG. 9 functions to throttle the ejector whenit is dead-ended but provides a plurality of chambers both to increasethe silencing and self-pressure regulating effects. That is, the casing611 carries a slidable plug 620 having multi-jet nozzles 625. A fixeddisk 615 at the bottom of the deep counterbore has a central orifice616. intermediate the disk 615 is a disk 635 having a plurality oflateral orifices 636 and also serving as a guide for a valve 637 carriedby the plug 620, the valve throttling the orifice 616 when the plug isretracted by dead ending.

Still other modifications and variations may be made by those skilled inthe art without departing from the spirit and scope of this invention asdefined in the following claims.

What is claimed is:

1. An air ejector comprising a casing having one end adapted to becoupled to a high-pressure air supply, a disk within said casing andhaving a central orifice therein, a plug member within the oppositedischarge end of said casing, said plug member having three or moreparallel and axially-extending passageways therethrough providing outletports at its discharge end, said passageways being substantially equallyspaced from each other and the longitudinal center line of said plugmember and connecting their outlet ports to inlet ports in an inletsurface of said plug member, whereby air passing through said diskorifice enters said inlet ports and is emitted from said outlet ports asparallel multiple jets, and valve means actuated as said outlet portscommence to be dead-ended against a surface to which said outlet portsare directed to throttle air passing through said central orifice.

2. An air ejector as defined in claim 1 in which said valving meanscomprises a valve stem slidably and centrally mounted in said plugmember and extending beyond said outlet ports, said valve stem having avalve head centrally located at said inlet surface of said plug, wherebythe commencement of dead-ending of said outlet ports and engagement ofthe protruding valve stem will push said valve head toward said centralorifice to throttle the same.

3. An air ejector as defined in claim 1 wherein said plug member isslidably mounted in said casing and normally pushed in the downstreamdirection of the movement of air through said ejector by the pressure ofair moving through said central orifice, whereby the pressure exerted onthe slidable plug member when dead-ending the ejector actuates thevalving means to throttle said central orifice.

4. An air ejector as defined in claim 3 in which said valving meanscomprises a headed valve stem member protruding upstream from the inletsurface of said plug member and normally spaced from said orifice,whereby the retraction of said plug member upon the commencement ofdead-ending causes said stem to throttle said orifice.

5. An air ejector as defined in claim 4 wherein a second disk isinterposed between said centrally-orificed disk, said second disk havinga plurality of lateral orifices and a central opening to guide saidvalve stem whereby a plurality of sound-deadening and backturbulencecreating chambers are provided between said orificed disk and the inletsurface of said plug member.

6. An air ejector as defined in claim 3, wherein said central orifice insaid disk is a short tubular portion extending downstream and the inletsurface of said plug member is dished downstream, whereby retraction ofsaid plug member upon the commencement of dead ending moves the inletsurface of said plug member toward said central orifice to throttle thesame.

7. An air ejector as defined in claim 6 wherein the central dishedportion of said inlet surface carries a valve head member protrudingtoward said orifice tube.

8. An air ejector as defined in claim 3 in which said centrally-orificeddisk is carried by said plug member over a dished inlet surface of saidplug member to provide a sound-deadening and back-turbulence creatingchamber between said dished inlet surface and said disk, a fixed seconddisk member is carried in said casing upstream of said first disk, and acentrally located downstream-extending valve stem. carried by said secured disk, said second disk having laterally located orifices to permitthe passage of air around its central valve stem, whereby retraction ofsaid plug member into said casing upon the commencement of deadendingpushes said first disk toward said valve stem to throttle the orifice insaid first disk.

9; An air ejector as defined in claim 3, in which a first disk having acentral orifice is fixed upstream and normally spaced from said plugmember, said plug member has a dished inlet surface covered by a seconddisk having lateral orifices therethrough to form a backturbulencecreating chamber between said plug and said second disk, a valve memberlocated centrally on said second disk and extending upstream toward thesaid central orifice to throttle the same when said plug member isretracted into said casing upon the commencement of dead-ending theejector.

1. An air ejector comprising a casing having one end adapted to becoupled to a high-pressure air supply, a disk within said casing andhaving a central orifice therein, a plug member within the oppositedischarge end of said casing, said plug member having three or moreparallel and axially-extending passageways therethrough providing outletports at its discharge end, said passageways being substantially equallyspaced from each other and the longitudinal center line of said plugmember and connecting their outlet ports to inlet ports in an inletsurface of said plug member, whereby air passing through said diskorifice enters said inlet ports and is emitted from said outlet ports asparallel multiple jets, and valve means actuated as said outlet portscommence to be dead-ended against a surface to which said outlet portsare directed to throttle air passing through said central orifice.
 2. Anair ejector as defined in claim 1 in which said valving means comprisesa valve stem slidably and centrally mounted in said plug member andextending beyond said outlet ports, said valve stem having a valve headcentrally located at said inlet surface of said plug, whereby thecommencement of dead-ending of said outlet ports and engagement of theprotruding valve stem will push said valve head toward said centralorifice to throttle the same.
 3. An air ejector as defined in claim 1wherein said plug member is slidably mounted in said casing and normallypushed in the downstream direction of the movement of air through saidejector by the pressure of air moving through said central orifice,whereby the pressure exerted on the slidable plug member whendead-ending the ejector actuates the valving means to throttle saidcentral orifice.
 4. An air ejector as defined in claim 3 in which saidvalving means comprises a headed valve stem member protruding upstreamfrom the inlet surface of said plug member and normally spaced from saidorifice, whereby the retraction of said plug member upon thecommencement of dead-ending causes said stem to throttle said orifice.5. An air ejector as defined in claim 4 wherein a second disk isinterposed between said centrally orificed disk, said second disk havinga plurality of lateral orifices and a central opening to guide saidvalve stem whereby a plurality of sound-deadening and back-turbulencecreating chambers are provided between said orificed disk and the inletsurface of said plug member.
 6. An air ejector as defined in claim 3,wherein said central orifice in said disk is a short tubular portionextending downstream and the inlet surface of said plug member is disheddownstream, whereby retraction of said plug member upon the commencementof dead-ending moves the inlet surface of said plug member toward saidcentral orifice to throttle the same.
 7. An air ejector as defined inclaim 6 wherein the central dished portion of said inlet surface carriesa valve head member protruding toward said orifice tube.
 8. An airejector as defined in claim 3 in which said centrally-orificed disk iscarried by said plug member over a dished inlet surface of said plugmember to provide a sound-deadening and back-turbulence creating chamberbetween said dished inlet surface and said disk, a fixed second diskmember is carried in said casing upstream of said first disk, and acentrally located downstream-extending valve stem carried by saidsecured disk, said second disk having laterally located orifices topermit the passage of air around its central valve stem, wherebyretraction of said plug member into said casing upon the commEncement ofdead-ending pushes said first disk toward said valve stem to throttlethe orifice in said first disk.
 9. An air ejector as defined in claim 3,in which a first disk having a central orifice is fixed upstream andnormally spaced from said plug member, said plug member has a dishedinlet surface covered by a second disk having lateral orificestherethrough to form a back-turbulence creating chamber between saidplug and said second disk, a valve member located centrally on saidsecond disk and extending upstream toward the said central orifice tothrottle the same when said plug member is retracted into said casingupon the commencement of dead-ending the ejector.